Lesson- Air, Topic -Oxygen, Term- 2

1. OXYGEN
From Science Book
Standard-8, Term-2,
PPT Prepared by,
P
.P
.EVELIN BANU.

2. Basic needs essential for human life..

9. Oxygen

10. Discovery of Oxygen
 C.W.Scheele in 1772
-Fire air or Vital life
 Joseph Priestley in 1774
 Lavoisier named oxygen

11. Occurrence
 Most abundant element on earth
 3rd after Hydrogen and Helium in the
universe
 Free state as O2
 Combined state as silicates and metal
oxides
 In water
 O3 as Upper layer of the atmosphere

12. Physical Properties
 Colourless
 Odourless
 Tasteless

13. Physical Properties
Poor conductor of heat and
electricity
Dissolves readily in water
Denser than air

14. Physical Properties
 Can be made into liquid at
high pressure and low
temperature
Supports combustion

15. Chemical Properties
 Non Combustible

17. Chemical Properties

18. Chemical Properties

19. Chemical Properties
Rusting

20. Uses
Respiration
Synthesis of methanol and ammonia
Explosives
Oxy-acetylene light for
cutting and welding metals
Oxidize rocket fuel
Removing carbon impurities

21. Thank you..